Field of the Invention
The present invention relates to an authentication technique in communication using ports of protocols supported as standard by an operation system (OS), such as the Internet Printing Protocol (IPP).
Description of the Related Art
When performing print processing in an information processing apparatus (such as a client terminal) on which an OS operates, it is possible to specify a standard port monitor built in the OS and instruct the standard port monitor to perform printing. The standard port monitor can transmit print data generated by a printer driver from a client terminal to a printing apparatus.
Also in a printing system including a print server in addition to a client terminal and a printing apparatus, a user is able to input print data to the print server by specifying a standard port monitor and issuing a printing instruction to a virtual printer managed on the print server. The print data input to the virtual printer of the print server is subsequently transmitted to the printing apparatus by using a function of the virtual printer and then printed.
In the above-described printing system, a proxy server may exist between the client terminal and the print server. For example, printing by the Internet Print Protocol (IPP) using standard ports of the Windows (registered trademark) system operates based on proxy settings of the OS.
When the client terminal inputs print data to the print server by using the IPP, a spooler system for managing ports on the client terminal transmits a request to the proxy server. In communication between the spooler system and the proxy server, proxy authentication is required. When this authentication fails, the proxy server transmits a proxy authentication error notification to the spooler system.
Japanese Patent Application Laid-Open No. 2012-84081 which is a conventional technique discusses a method for prompting a user to manually input authentication information if an authentication error occurs between an application and a proxy server.
In this case, according the OS specifications, when a spooler system itself transmits a request to the proxy server, the spooler system transmits authentication information managed by the spooler system itself in response to a proxy authentication error notification from the proxy server. This processing causes proxy authentication to be performed on the proxy server.
The above-described standard port monitor built in the OS is provided only with a simple function of transmitting print data. For example, in the case of temporary communication breakdown during data transmission, an error occurs without undergoing retry processing. More specifically, the standard port monitor is not provided with sufficient communication control and retry processing functions required in print data transfer. Therefore, a printing apparatus vendor offers a custom port monitor implementing such communication control and retry processing functions to be used instead of the standard port monitor.
On the other hand, in an environment of a new OS such as Microsoft Windows (registered trademark) 8, a new printing system has been implemented. In the printing system, a custom port monitor offered by a printer vendor cannot be registered and only the standard port monitor is to be used.
To implement the above-described communication control and retry processing functions even under the new OS environment, it is conceivable to provide a communication control module for mediating communication (such as a request) between the standard port monitor of the client terminal instead of the custom port monitor, and the print server as an agent. Then, such an agent module transfers print data while implementing required communication control and retry processing.
However, even when an agent module is used, there is a problem that proxy authentication cannot be performed in a case where a proxy server exists between the agent module and the print server.
In the case of printing performed via the above-described agent module, the spooler system which manages ports transmits a request to the Uniform Resource Locator (URL) corresponding to the agent module. Then, the agent module forwards a request to the print server via the proxy server. Suppose that a proxy authentication error occurs between the agent module and the proxy server in this case. Naturally, the agent module notifies the spooler system of the proxy authentication error. However, according to the OS specifications, the spooler system is configured not to transmit the authentication information in response to such a proxy authentication error notification since the spooler system itself has not transmitted a request to the proxy server. As a result, proxy authentication fails in IPP-based printing performed via the agent module.
As discussed in Japanese Patent Application Laid-Open No. 2012-84081, it is conceivable to offer a mechanism for causing a user to input authentication information via an agent module upon occurrence of a proxy authentication error. In this case, however, although the user has set the authentication information in advance to the OS, user convenience is deteriorated since authentication information needs to be manually re-input each time printing is performed via the agent module.
Further, it is not possible to realize an unmanned printing system in which, for example, a print job is entered from a client terminal to a print server.